Characterization of the Thin Oxide-Nitride-Oxide (ONO) Structure Using Spectroscopic Ellipsometry

1994 ◽  
Vol 358 ◽  
Author(s):  
Leo M. Asinovsky ◽  
Steve Zierer

ABSTRACTSpectroscopic ellipsometry has been used to characterize thin oxide/nitride/oxide (ONO) layer structures. Films were deposited on top of the Si/oxide/polysilicon filmstack using a low-pressure chemical vapor deposition (LPCVD) technique. Different approaches to modeling this structure are compared to select an adequate representation. Analysis of the data for the three-layer-with-abrupt-interfaces ONO model using an effective-medium or Cauchy approximation shows strong correlation of the parameters and ambiguity of the results. A more robust and physically plausible model of the ONO structure as an inhomogeneous oxynitride film with Gaussian distribution of the silicon nitride component is suggested. This interpretation of the ONO structure is supported by the results of Auger electron spectroscopy (AES) and transmission electron microscopy (XTEM).

1993 ◽  
Vol 324 ◽  
Author(s):  
L.M. Asinovsky

AbstractSpectroscopic ellipsometry has been used to characterize oxide/poly-Si/oxide with thin nitride/oxide layer. Films were deposited on Si substrate using low-pressure chemical vapor deposition (LPCVD) techniques. The measurements were taken at angles of incidence of 65 and 70 degrees in the wavelength range from 300 to 800 nm. The analysis of the data using effective medium and two-dimensional Lorentz oscillator approximations identified complete recrystallization of the poly-Si after annealing and and its transformation to µ c-Si. Three wafers taken at the sequential stages of the manufacturing process were studied. Although parameters of the thin nitride/oxide layers are strongly correlated, reasonable estimates of the thicknesses were found. The resuilts were consistent with the measured Auger electron spectroscopy (AES) profiles.


1991 ◽  
Vol 220 ◽  
Author(s):  
F. Namavar ◽  
J. M. Manke ◽  
E. P. Kvam ◽  
M. M. Sanfacon ◽  
C. H. Perry ◽  
...  

ABSTRACTThe objective of this paper is to demonstrate the epitaxial growth of SiGe strained layers using atmospheric-pressure chemical vapor deposition (APCVD). We have grown SiGe layers with various thicknesses and Ge concentrations at temperatures ranging from 800–1000°C. The samples were studied using a variety of methods, including transmission electron microscopy (TEM), high resolution X-ray diffraction (HRXRD) and Raman spectroscopy (RS). Both HRXRD and RS results indicate that samples with about 10% Ge and a thickness of about 1000 Å are almost fully strained. TEM analyses of these samples indicate a film defect density less than 105/cm2. SIMS results indicate that the oxygen concentration in the epitaxial layers is lower than that found in CZ substrates.Our analyses also indicate that as-grown epitaxial Ge layers several microns thick have a defect density less than 107/cm2. The relatively low defect density in both SiGe and Ge layers grown on Si has been attributed to far higher dislocation glide velocity at the relatively elevated growth temperatures employed in CVD and to very good growth cleanliness.


1991 ◽  
Vol 238 ◽  
Author(s):  
Paul G. Snyder ◽  
Yi-Ming Xiong ◽  
John A. Woollam ◽  
Eric R. Krosche

ABSTRACTVariable angle spectroscopie ellipsometry (VASE), a nondestructive optical technique, was used to characterize two different multilayer samples, each having a low-pressure chemical vapor deposited polycrystalline silicon (poly-Si) layer. Analysis of these samples by cross-sectional transmission electron microscopy (XTEM) revealed large changes in grain size, between the undoped, as-deposited, and doped, annealed poly-Si layers. Roughness at the top of the poly-Si layers was also observed by XTEM. These features, together with the other structure parameters (thickness and composition), were analyzed ellipsometrically by fitting the measured VASE spectra with appropriate multilayer models. Each composite layer (surface overlayer, interfacial layer, and poly-Si layer) was modeled as a physical mixture, using the Bruggeman effective medium approximation. The ellipsometrically determined thicknesses were in very good agreement with the corresponding results measured by XTEM. Furthermore, VASE analysis provided additional information about the relative fractions of the constituent materials in the different composite layers. Thus, it quantitatively characterized the surface and interracial properties, and also the doping and annealing effects on the microstructure of poly-Si layers.


1992 ◽  
Vol 283 ◽  
Author(s):  
C. Manfredotti ◽  
F. Fizzotti ◽  
G. Amato ◽  
L. Boarino ◽  
M. Abbas

ABSTRACTBoth B- and P- doped silicon films deposited by Low Pressure Chemical Vapor Deposition (LPCVD) at 300 °C (p-type) and 420 °C (n-type) have been characterized by optical absorption, Photothermal Deflection Spectroscopy (PDS), resistivity, Elastic Recoil Detection Analysis (ERDA), Transmission Electron Microscopy (TEM), Convergent-Beam Electron Diffraction (CBED) and Raman spectroscopy measurements. P-doped films, deposited at large PH3 flux rates, show a high degree of microcrystallinity, indicating that P activates the nucleation process even at low temperatures. In this case, values of activation energy of resistivity as low as 0.007 eV were obtained. Both TEM and RAMAN results confirm a volume percentage of micro crystallinity above 30%. On the contrary, B-doped samples are not microcrystalline at least in the doping range investigated, and show a behaviour not different from samples deposited by PECVD.


1991 ◽  
Vol 220 ◽  
Author(s):  
P. D. Agnello ◽  
T. O. Sedgwick ◽  
M. S. Goorsky ◽  
J. Ott ◽  
T. S. Kuan ◽  
...  

ABSTRACTDichlorosilanc and germane were used to grow silicon-germanium alloys at temperatures as low as 550°C at atmospheric pressure. Germanium mole fractions as high as 44% were obtained and the layers exhibit smooth surface morphology. Silicon-gcrmanium/silicon multilayers with abrupt hctero-intcrfaccs have been achieved. Cross Section Transmission Electron Microscopy, (XTEM) and High Resolution X-Ray Diffraction, (HRXRD) characterization of the hetero-interface abruptness will be presented. Recent results on two-dimensional (2-D) hole mobility structures grown by this technique will also be reported. Selective growth of silicon-germanium on oxide patterned silicon wafers was also demonstrated. A significant feature of the selective deposition is the lack of faceting at the oxide sidcwall, which has been commonly observed in high temperature silicon growth.


2008 ◽  
Vol 18 (04) ◽  
pp. 901-910
Author(s):  
RAGNAR KIEBACH ◽  
ZHENRUI YU ◽  
MARIANO ACEVES-MIJARES ◽  
DONGCAI BIAN ◽  
JINHUI DU

The formation of nano sized Si structures during the annealing of silicon rich oxide (SRO) films was investigated. These films were synthesized by low pressure chemical vapor deposition (LPCVD) and used as precursors, a post-deposition thermal annealing leads to the formation of Si nano crystals in the SiO 2 matrix and Si nano islands ( Si nI ) at c-Si /SRO interface. The influences of the excess Si concentration, the incorporation of N in the SRO precursors, and the presence of a Si concentration gradient on the Si nI formation were studied. Additionally the influence of pre-deposition substrate surface treatments on the island formation was investigated. Therefore, the substrate surface was mechanical scratched, producing high density of net-like scratches on the surface. Scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM) were used to characterize the synthesized nano islands. Results show that above mentioned parameters have significant influences on the Si nIs . High density nanosized Si islands can epitaxially grow from the c-Si substrate. The reported method is very simple and completely compatible with Si integrated circuit technology.


2016 ◽  
Vol 874 ◽  
pp. 3-8
Author(s):  
Bo Wang ◽  
Zhen Yu Zhang ◽  
Neng Dong Duan ◽  
Ji Lei Lyu ◽  
Guo Xin Chen ◽  
...  

In this study, nanotwinned surface is fabricated on a Nickel alloy by means of a developed diamond panel with tips array. The diamond panel has an area of 10×10 mm2, and is grown using microwave chemical vapor deposition. The diamond tips are submicron in radius and formed on a silicon substrate with an array full of uniformed inverted pyramid pits. The nanotwinned surface is produced under the pressure of 1 MPa exerted by the diamond panel with tips array. Nanotwins are confirmed using transmission electron microscopy. The nanotwinned surface is generated by indention of diamond panel at room temperature using mechanical force, neither material removal nor chemical reagents. This is different from previous reports, in which high temperature, high pressure, chemical reagents or vacuum conditions are employed usually.


1989 ◽  
Vol 170 ◽  
Author(s):  
Seshu B. Desu ◽  
J. Ashley Taylor

AbstractThe reaction of sputtered deposited Ti films of 100 nm thick with low pressure chemical vapor deposited Si3N4 films (300 nm thick) was studied in N2 or Ar, in a rapid thermal annealer. Reactions are followed using x-ray diffraction, Auger electron spectroscopy, and transmission electron microscopy. In argon, the Si3N4 and Ti reaction at low temperatures led to the product formation of two layer structure (TiN/Ti5Si3), with some contaminant oxygen and nitrogen released from the reaction uniformly dissolved throughout the remaining unreacted Ti. At higher temperatures, a three layer structure, TiN/TixSiy/TiN, on unreacted Si3N4 was developed. With increasing temperature the value of x and y decreased from 5 to 0 and 3 to 1, respectively. Reactions in N2 ambient, irrespective of temperature, always produced the three layer structure, but the thickness of TixSiy layer was much smaller than that produced in argon ambient for the corresponding temperatures. The reaction mechanism can be explained in terms of relative diffusion coefficients and the stability of the interfaces.


2010 ◽  
Vol 1258 ◽  
Author(s):  
Andrés Rodríguez ◽  
Jesús Sangrador ◽  
Tomás Rodríguez ◽  
Carmen Ballesteros ◽  
Carmelo Prieto ◽  
...  

AbstractSiGe nanowires were grown by the vapor-liquid-solid method using a low pressure chemical vapor deposition reactor and different flows of the GeH4 and Si2H6 gas precursors. The morphology of the nanowires was studied by field emission scanning electron microscopy, and the length, diameter and density of nanowires were determined. Their structure and crystallinity were analyzed by transmission electron microscopy and its related techniques. Energy dispersive X-ray emission of individual nanowires as well a Raman spectroscopy were used to determine their composition and to analyze its homogeneity.


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